PP23C-2315
Late Pleistocene Rapid Climate Change Events Measured in Stalagmites From a Semi-Arid Cave in Iran Show Pan-Eurasian Climate Signal Matching NGRIP
Tuesday, 15 December 2015
Poster Hall (Moscone South)
Sevag Mehterian1, Ali Pourmand2, Arash Sharifi3, Lisa Murphy1, Hamid A.K. Lahijani4, Majid Naderi4 and Peter K Swart5, (1)University of Miami, Miami, FL, United States, (2)University of Miami, 1- Neptune Isotope Laboratory (NIL), Department of Marine Geosciences, , Rosenstiel School of Marine and Atmospheric Science, Miami, FL, United States, (3)University of Miami, Neptune Isotope Laboratory (NIL), Department of Marine Geosciences, , Rosenstiel School of Marine and Atmospheric Science, Miami, FL, United States, (4)Iranian National Institute for Oceanography and Atmospheric Science, Marine Geology, Tehran, Iran, (5)University of Miami, Department of Marine Geosciences - RSMAS, Miami, FL, United States
Abstract:
Although new records of Pleistocene climate variability have begun to emerge from speleothems in Western and Eastern Asia, much remains unknown about climate variability on centennial to millennial timescales during the last glacial and interglacial periods across the interior of West Asia. The regional climate of West Asia is governed by interactions between the Northern Hemisphere Westerly Jet, the Siberian Anticyclone and the Indian Ocean Summer Monsoon, making this region highly sensitive to abrupt climate variability. Here we present the first high-resolution oxygen isotope record of two stalagmites from a cave in the semi-arid region of NW Iran. The records from Qaleh Kord Cave (QKC, 35°47'50”N, 48°51'25"E) span between 73 kya to 127 kya and cover marine isotope stages MIS4 and MIS5. The absolute chronology of both stalagmites was established using a novel high-precision U-Th geochronometry technique with multi-collection ICP-MS. The δ18O composition of QKC stalagmites closely agree with changes in δ18O composition of the NGRIP ice core from Greenland, indicating a close atmospheric teleconnection between the climate of the North Atlantic and the interior of West Asia during this period. Because the chronology of NGRIP beyond 60 kya is calculated via numerical flow models and not directly measured, data from our stalagmites provide absolute age tie points to improve the accuracy of the deepest portion of the ice record. Furthermore, agreement between our records and those from the Soreq (Israel) and Sanbao (China) caves in West and East Asia point to a pan-Eurasian climate signal. In order to investigate the mechanisms that drive changes in climate in Western Asia on millennial timescales and examine the role of orbital characteristics and changes in insolation on atmospheric circulation and precipitation during MIS5, we present results from fully-coupled general circulation simulation CESM1 at three time slices of 80, 95, and 115 kya.
